The present invention relates to a prefabricated shower base assembly for tile and stone applications in showers.
Tile and stone covered showers have been used for many years; however, construction methods for constructing showers and wet areas have changed dramatically such that construction of a sub-base is necessary to provide support for tile or stone floor surfaces. For example, waterproofing beneath the tile or stone is particularly necessary in multi-story constructions with living space beneath the shower area. This led to the creation/use of waterproof envelopes/barriers under the tile or stone, known as “shower pans.” Early shower pans were constructed of copper, sheet metal or sheet lead, and were clamped to the drain typically with a clamping flange. These pans were then filled with a Portland cement and sand mixture, so that, when cured, they provided a base that was acceptable for bonding tile and stone. However, these types of shower pans were/are difficult and time-consuming to construct, and they were/are prone to leaking.
As new materials came into existence, better waterproofing systems evolved such as liquid and thermoplastic membranes that provided superior waterproofing characteristics and that made installation easier over traditional lead and copper pans. Although this improved the integrity of the waterproofing, it still requires skilled labor to install the mortar bed on the pan. It also requires curing of the mortar bed prior to installation of the tile or stone, which takes time and potentially leads to inefficient use of skilled manpower due to the necessity of more than one visit by the skilled workers to the installations.
As land and infrastructure costs have increased, residential homes and condominiums of multi-floor design have also increased. However, this increased density has created problems in the area of sound transmission between floors and ceilings of units above and below. The sound created by normal activity is transmitted through floors and is typically referred to as “Impact Sound.” Bathrooms tend to be difficult areas to reduce the level of impact sound transmission to the unit below since a majority of bathroom areas are covered with ceramic tile or natural stone where transmission of sound through the floor becomes an issue. Since virtually all sound reduction materials are installed under the finish flooring, the area under a shower floor is not able to be isolated. Also, many bathroom “furniture” and structural articles, such as ceramic and/or metal toilets, tubs, sinks, countertops and pipes, can be sound generators and/or sound carriers, making it difficult to achieve a satisfactorily “quiet” bathroom area.
In the United States and Canada, the most common drain that is used in shower and wet area installations is the “clamping ring drain.” They are typically manufactured in cast iron, PVC and ABS materials and are available from a vast number of distributors and outlets. Depending on local building codes, installation of the drain most often falls under the plumbing code. However, the responsibility for the waterproof integrity and flood testing of the installation most often lies on the plumber. This requires coordination of skilled trades, which can lead to inefficiencies and hence higher costs during installation.
Some companies have attempted to provide pre-manufactured shower bases and trays, attempting to reduce the amount of skilled labor time required for installations. However, the existing known pre-manufactured shower bases and trays do not permit adjustment in a back-to-front direction, nor in a side-to-side direction, nor diagonally, in order to match drain (and wall) locations. Floor drains also cannot be adjusted once rough-in piping is set during early stages of construction. Thus, in known systems, the floor drain must be precisely located in the shower floor relative to shower walls during building construction, and the location of the drain opening in pre-manufactured shower bases must be accurately cut to match, which is very difficult to do on a consistent basis in “real world” building constructions. Further, pre-manufactured shower bases and trays often still require repeated trips back to the installation site by skilled trades, thus still resulting in greater installation costs than desired. Still further, grout and tile are relatively brittle and very sensitive to any deflection, which leads to cracking when the floor flexes or is stressed, which in turn leads to water leak problems. Thus, rigidity and stability is very important in the supporting structure. Yet some pre-manufactured shower bases arguably provide only marginal rigidity and stability.